Chef’s first to forsake moreish ingredient (8)
I believe the answer is:
additive
'ingredient' is the definition.
(I've seen this before)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for additive that I've seen before include "Something put into food" , "Eg, a colorant or preservative in foods" , "Substance put into food" , "Produced by summing" , "ingredient" .)